Thrust bearing adjusting mechanism



p 1933- A. F. SCHWENDNEIR 1,926,562

THRUST BEARING ADJUSTING MECHANISM Filed Dec. 2, 1952 2 Sheets-Sheet 1 INVENTOR FIG.4.

A TTORNEY ANTHONY ES HwENDNER.

Sept. 12, 1933. A. F. SCHWENDNER THRUST BEARING ADJUSTING MECBANISM Filed Dec. 2, 1932 2 Sheets-Sheet 2 FIG 5 IN VENTOR HNTHONY F'. 5CHWENDNEE.

RNEY

i AnthonyflrschwendnenEssingtonfla assignor to Westinghouse Electric v &YManufacturingl v *elastic fluid turbine ened blading embodied in the turbine; fig. 3 is a detail view showing the Big. 4 is a transverse sectionalvi'ew taken along the line IV--IV lofyFig. 5; and "f-Fig. 5 is a longitudinal view. improved bearing with parts broken away1for 'clear'ness.

p yrEfiSt Pittsburgh, Pa, a, corporati 7 0f Bennsylvania 7 This invention relates to thru stbearings such as are used, for example, on elastie -fluid turbines,

and it has for an object (to provideimproved means for adjusting the thrust fbearingiaxially while under load. v .t

Inthe operationo f,elast ic fluid turbines becomes necessary at times to move the spindle shaft axiallylwith respect to the casing to obtain proper blade clearance It has been :proposed to" i move the spindle shaft and (the thrust member of the bearing axiallyby mechanical means in cludinga hand wheel and gearing or screws;- howevenon' large machines when the thrust is great, it becomesdiflicult to actuaitethehand- 1y large parts are required-1 o. effect the adjust-f ;In accordance withmy invention, I provide a fluid pressure actuated devicewhich will remove load'f rom the adjusting means while foperating';

the same. 1 preferably provide the thrust member of the bearingwith a piston whichjis diss posed within a cylinder fermed withinthe bear ing housing. When thethrust memb ervis tofbe moved, fluid pressure is applied to thellpiston in. opposition to the thr.ust-.thereon;to substantially .Theseand other objects areeffected vention as will be apparent irorn-fthe following description and clairns taken in connectionfwithn the accompanying drawingskforrning a part of this application, in whichg Fig. l isa'longitudinal view'in sectionb an including my 7 improved bearing; i Fig.2 is a detail view showing the end-tightend-ti ht,- ened or axial clearance dummy packing embodied in the turbine; I

in section of iny Referring'n'ow V turbine including a casing lo l-within which a across each rowoff i'i'iovinghlades 13. The blades" l3. and iliand the dummy; packing are of a type also PTOVidQdQWithI i ditightened *or axial clearlance pack ng elements 8" and 9, respectively, to restrict-leakageiof motive fiuid st t mm e e e to the leftian'd wheel because of excessive friction, and relativemeral 1'7. In the present segment 6 15,4193 f spindle iii, dummy pistonsl 'lla and having a shaft 12, 'is-"rotatively Imounted.i"Fixed to thefspindle i;1" i and the casing 10 arefreaction'blades 1 am 14,,"respective1y,f there being "a {arssiirejdrop whose packingiclearances may bevaried'hy relative axial mover ent. v "-As shown in Fig. 2, the bladesare preierably of the end tightened' type that is, jblades having.packing'eleinents '13 and.

14 which-restrict leakage of motive fluid. around the (tips offthejbladejs by providing ciose axial clearances. fThe'casing 1 0 andthe spindle 11 are pistons- 11d; i Theaxiahcleaiancij inboth-cases, are increased upon'imov merit of the spindle 11 right. 1

i 1 The asing 16 is iprovided lwith an init iisf an as outletl 'ld for motiveffiuid;whichqfluid is, ex-

decreased 'uifion"movement mine 'pa'nded as'lit passes through the passages formed 7 bygblade's is a a 14, producing rotation r the spindle in a well1 known tmanner. Due to the pressure drops'acrossi therowsof moving blades,

there strust thrust'flto the leftfa's viewed. in ,f I Rig; 1', whichfis' partially orgwliollybalanced' by-v dummy pisto'iist lli. The resultant thrust, which may be" to the rightfo r to lthelleft according; to the particular design, istr'ansmitted to athrust bearing structure indicated generallyjby; thenu ant thrust is toltheright;

p sses the. {small running elearances 1 renj-i denng the turbine subject 5min rub, r Thefs'pi ndle" 1 1; is. moved to provide;extra 'large clearances,V Q 7 untilfthe spindle 1 'a'n'dfca'sing'i oj are uniformly, 3

neme to ijedu the possibility of, rubbing.

axially; to 'properlyjpositionthe same with respectjtonie casing 1p; Themechan'isin for efi-f fee-ting axial movement of the spindle 11' is dis-.

closed 'in Figsf and 5 towhich reierence will now be had. e

embdimem thires le 1 "In starting, t1 spindle'll andith eingyimi 99 likelyl to.;bejsomewhatflist rtedtbecauseofu inieqiial" temperature distribution ,takinggup in i The thrustbearingstructure l'lfiincludes a j 1 i v housing-19 within whichfi is rdisp' thrust t Fig, 1, I owelastic fluid member 21 having hearing segments 22 arranged 23 which is fired to the shaft 12. The thrust collar 23 is positioned axially by the segments 22.

A nut 24 is threaded to the thrust'member 21 and hasteeth 25 formed'on its outer face which mesh with a worm 26 fixed to a stem 27. ,The stem 27 is journaled in'thehou'sing l9 and is secured to the'handwheel 18 at its outer' end.

It will be seen that rotation of the handwheel 18, the stem 27 and worm 26 will cause the nut 24 to rotate about the thrust member 21;. Axial movement of the nut 24 is prevented by.projec-.

tions 28 which extendinwardlyfrom theinner surface of thehousing 19. I Thenut 24 is of slightly less width than the space between 'theproe.

jections 28, so that a small clearance, for example, .007 inch, is provided between-the nut 24 and one of the projections23 for a purposewhich will hereinafter be made apparent. As the nut I 24 is threaded to the thrust member 21, rotation" of the formerwill produce an axial movement of the latter. Rotation of the thrust member '21 about theshaft is prevented byfextensions 31' carried by the thrust "member which bear against pads 32ffor med on'the housing'19i 7 With relativelylarge bearings where the thrust is "great, the friction incidental to: movement of the thrust member21 may be eggcssivefrendering manual operation of the handwheel 18 diflicult. ,In order-to overcome this difficulty,l neutralize the thrust on the member, 21 by applying fiuid pressure to the same-in opposition .to the thrust. The sliding friction ofthe threaded connection' 24a and of the nut 241against projections 28 is greatly reduced, sojthatresistance tomove- 21161113 of the handwheel '18 is very low. Accord ingly fI provide a cylinder 33: within the housing 19 having apiston 34 disposed therein, which piston 34 is carried byLthe member Zlf and'movable axially therewithfl' s The control and supply of motivating fluid for moving the'piston 34 may} be effected in any well known manner, but]; prefer to use the arrangement shown in Fig. 5. "Inithis arrangemehh'a pump 35 having an impeller 36' secured to the shaft" 21 isutilizedl The'pump '35 hasan inlet- 3"? communicating with a chamber 38 'forrned'inthe housing 19 which chamber 38 communicates with asupply of fluid. The pump35 also has an out-a ofthe'leylinder 33'." Conduit 41' is'adapted to. CQIII! municate with conduits 43 and 44. through valves 47 and 45,' respectively, and conduit'42 is adapted valves 48 and '46, respectively.

.t fl m' l r ewi h dui .3'la'ed 44 h i sh' Assume it isdesiredtoadju the turbine shown inFig.1.' Here the thrustiis to s re must be admitted to the'portion 52 or the cylinder 33. The valves 46 and 47 are opened a and respectively connect the outlet .39 of the pump 35; to the cylinder portion. 52 and .the chamber 33 to-the portion .51 of the. cylinder 33'. 'Fluid 7 pressure is, therefore, providedinihe cylinder portion 52 which tends to. move the piston '34 and the member 21 to the left in opposition to-the thrust thereon. Resistanceto movement of ,the

,nut 24 and'worm 26 is, therefore, substantially :reduced', and movement of the handwheel 18 is "easily effected. Thethrustmember 21 is .the

' wheel 18;

st thel spindle 1 1 in Ina 'in I the right, so that to oppose this thrust, fluid presmoved either right orleft as desired until the spindle 11 has assumed its'proper position. The valve 46 may then be closedto shut off I the fluid pressure to the piston 34, allowing the thrust to be transmitted through the nut 24 while the same is not being actuated. In the event that the thrust is in the opposite direction or to the right,

as viewed in Figs. 1 and 5, fluid pressure would then be admitted to cylinder portion 51 through .Jconduit 42, valve 48, and conduit 43 when an adjustment or" the bearing is made. In this event cylinder portion52 would be connected to chamber'38 through conduit 49, valve 45 and conduit '41. v

The value of the thrust acting. on the member 21 maybe determined bymeasuring the pressure acting on the piston 34. Pressure gauges 54 and 55 are connected to the conduits 43 and 44, respectively, and are preferably calibrated in pounds of thrust. The valve 46, or the valve 48, depending on the direction of thrust, is slowly opened, allowing pressure in thecorresponding portion of the cylinder 33 to build up slowly. When the han'dwheellS turns mostfreely, the fluid pressure in the cylinder 33 is balancing the Zthr'uStand the reading of the corresponding gauge will indicate the value of the thrust.

In theconstruction' described above, the me- .chanical adjusting means provides for definitely ,locating th'e axialposition of the spindle, while the pressure actuated means provides the necesbe controlledby "the application of a relatively light force, manual orotherwise, to the hand- A further advantage of the above'mechanism'is found in connection with the grinding in of the packing elements by actual contact with thecosary' force to oppose the'thrust while the axial. position is being changed. By this combination, v therefore, the axial position of the spindle may operating packing surfaces in order toinsure uniform. packing clearances throughout; With my mechanism, taking .theabove embodiment as 'an example, this may be accomplished as follows: Fluid pressure is admitted to the cylinder portion 52, moving the spindle "to the left until the-clearance betweenthe left hand sideof the nut '24- andthe adjacent projection 28 is taken. up; that is, .it moves" about 007 inch. The spindle is then adjusted by mean's of the handwheel '18,jto*a" clearance which is less thanthe clearance between the nut 24 and the'projection'28 on the right-hand side,- forexample,-aclearance of .005 inch may be provided. The fluid pressure in the. cylinderportion '52 is then released for ,a few seconds, duringwhich the packing elements come into actuallcontact with theircooperating packing suriaces therebygrinding off the thin Thisgprocedure-must be carried on intermittent1y, due to the fact that the' grinding produce'sallarge' amount of heat.- After a few sec" 'onds of grinding, the packing elements mustbe taken out of contact and. allowed to cool. v lli-h my'mechanism', this is easilyaccomplished by applying pressure to the cylinder portion 52' to move the spindle to the leftin clearanceincreasjing direction. After the packing elements have oooled, sufficiently, the pressure. is discharged,

and. the thrust again moves the spindle to the right to bring the packing elementsinto contact for further grinding. 5 If; necessary, the handwheel 18 may be operated to move the spindle farther to the right for furthergrinding. While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is notso limited but is susceptible of various changes and modifications without departing, from the spirit thereof, and Idesire, therefore that only such limitations shall be placed "thereupon as are imposed by the prior art or as are specifically set forthin the appended claims. I V 7 What I claimiszg V 1'. In a thrust bearing adjusting mechanism, the combination of a housing, a rotatable; shaft mountedin saidhousing and having a thrust collar, a bearingrneinber engaging the thrust collar, mechanical means'for moving the bearing member in the housing, and means for applying fluid pressure to the bearing member in opposition to the thrust imposed thereon where-- by said mechanical means may readily move the bearing member.

2. In a thrust bearing adjusting-mechanism,

' the combination of a stationary casing,- anaxially movable thrust member mounted in said casing, a shaft mounted in said casing, a thrust said thrust member, means for mechanically moving the thrust member axially and for fixing the axial position thereof, and means for applying fluid pressure to the thrust member for neu-' tralizing the axial thrust thereon, thereby reducing the load on said means while 'moving the thrustmember. ,1 r

3. In a thrust bearing adjusting mechanism, thecombination of -a stationary casing having a cylinder portion formed therein, an axially m'ov v able thrust member mounted in said casing and having a piston portion disposed within said cylinder portion, a shaft mounted in said casing, a thrust collar carried by said shaft and engag ing said thrust member, mechanical means for. 1 moving said thrust member axially'of the shaft,

and means for applying fluid pressureto said piston' for biasing'the thrust member in opposition to the thrust thereon, thereby reducing the' load on said mechanical means while moving the thrust member."

4. In a thrust bearing adjusting mechanism,

the combination of a stationary casingan' ax ially movable thrust member mounted in said casing, a shaft mounted in said casing, a thrust collarcarried by said shaft and bearing against 3 said thrust member, means for mechanically moving the thrust member axially and for fixing the axial position thereof, means for applying fluid pressureto the thrust member for neutral "hung the axial thrust thereon, thereby reducing the load on said means While moving the thrust member, and mean'sflfor indicating the thrust on said member.

-5. In a thrust bearing adjusting mechanism,

the combination of a stationary casing having a' cylinder portion formed therein, an axially mov :able thrust member mounted in said casing and having a piston disposed within said cylinder portion,"a shaft mounted in said casing, a thrust collar carried by said shaft and engaging said' respect to said structure.

thrust member, mechanical means for moving said thrust member axially of the shaft, means for applying fluid pressure to said piston for biasing the thrust member in opposition to the thrust thereon, thereby reducingthe load on saidmechanical means while moving the thrust member, and indicating means actuated by said fluid pressure for recording the thrust on said 7 member. 7

6. In a thrust bearing posed thereon and having a thrust collar, a

thrust member engaging saidthrust collar, me-

chanical means-for adjusting' the axial position .of the thrust member, and means for applying a force to the thrust member infopposition to the thrust imposed thereon, whereby the stress adjusting mechanism, the combination of an axially movable and rotatable shaft adapted to have an axialthrust-imimposed on the adjusting means may be reduced 'means for adjusting the axial position of the collar carried by said shaft and bearing against thrust member; and means for applying fluid pressure to the thrust member in, opposition to the thrust irnposed thereon,gwhereby the stress imposed on the adjusting means may be reduced while adjusting the thrust bearing member. 1

8. In a thrust bearingfmechanism, the combination of an axially movable and rotatable shaft adapted to have an axial thrust imposed thereon and having a thrust collar, a thrust bearing member'engaging said" thrustcollar, a structure. for receiving theaxial thrust from tlie'thrust bearing member, means for transmitting thrust from the thrust bearing member to said structure and for adjusting the thrust bearing member axially with respect to said structure, andmeans for applying'a force to the thrust bearing member in opposition to thethrust thereon to reduce the thrust on'said adjustingmeans'while adjusting th'ethrust bearing member, said adjusting means 9. Ina thrust bearing adjusting mechanism, the combination jof Van axiallyvmovable and robeing adapted, after adjustment has been made, Y to receive the entire thrustimposed on the thrust bearing member.

tatable shaft adapted to have an axial thrust imv posed thereon and having a thrustbollar, a

thrust bearing member engaging. said thrust colla'r, a structure for receiving the; axial thrust from the thrust bearing member, a screw threade her and said structure for. transmitting axial thrust from the former to the latter and for move, a

ing the thrust bearing member axially and fixing the-axialposition thereof with respect to said structure, andvmeans for applying fluid pressure AnTHoNY n'sorrwnunNaa-r V v i I ".V145V ed connectionbetween thejthrustbearing mern- 

